1. Field of the Invention
The present invention relates to a touch screen, more specifically, to a touch screen that uses pressure to control the zoom ratio.
2. Description of the Prior Art
In modern society, computer systems are no longer viewed as costly toys reserved for the wealthy, but as necessities for ordinary people in their daily lives. Nowadays, nearly everyone has a computer system, such as a desktop computer, a laptop computer, or a personal digital assistant (PDA). Just as computer systems have become more advanced, computer monitors are constantly being redesigned to be thinner, lighter, and more convenient to use. One of the most recent innovations in computer monitor technology is the touch screen.
Among touch screens, there are two prior art that deal with zooming in on images. Please refer to FIG. 1A, FIG. 1B, and FIG. 1C. The FIG. 1A is a diagram of the unmagnified display 10 of a screen showing an image. FIG. 1B is a diagram of a display 20 showing an image magnified using the first method of magnification. FIG. 1C is a diagram of a display 30 showing an image magnified using the second method of magnification. The first prior art pertaining to magnification showed in FIG. 1B is magnifying the upper-left section of the imaged in FIG. 1A by a predetermined zoom ratio. If the user wants to view other parts of the image, he can control the horizontal scrolling bar 22 and vertical scrolling bar 24 to move to the part of the image he wishes to view. The second prior art pertaining to magnification shown in FIG. 1C is magnifying the part of the imaged in FIG. 1A under the zoom area 32 by a predetermined zoom ratio and displaying it in the zoom area 32. The user can move the zoom area 32 to view different parts of the imaged in FIG. 1A. This kind of operation simulates viewing the imaged in FIG. 1A under a magnifying glass.
Among the disadvantages of the two prior arts of magnification mentioned above is that it is not convenient to use a fixed zoom ratio for all zoom functions. It can also be cumbersome to use a zoom window that cannot be easily adjusted according to the needs of the user.
It is therefore an objective of the claimed invention to solve the problems mentioned above by providing a touch screen that uses pressure to control the zoom ratio.
The claimed touch screen, briefly summarized, comprises a display panel, a touch sensor, and a display control. A display panel is used to display an image. A touch sensor is used to sense the intensity and position of an external force and generate a corresponding pressure signal and position signal.
A display control is connected to the display panel and the touch sensor for controlling the image and zooming in on a portion of the image according to the pressure signal and position signals. A predetermined conversion model is used to derive the zoom ratio from the pressure signal generated by the touch sensor.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.